xref: /linux/arch/powerpc/kvm/book3s_64_mmu_radix.c (revision b76960c0f6b25d447a1493c4388defb9e8e76c63)
1 /*
2  * This program is free software; you can redistribute it and/or modify
3  * it under the terms of the GNU General Public License, version 2, as
4  * published by the Free Software Foundation.
5  *
6  * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/string.h>
11 #include <linux/kvm.h>
12 #include <linux/kvm_host.h>
13 
14 #include <asm/kvm_ppc.h>
15 #include <asm/kvm_book3s.h>
16 #include <asm/page.h>
17 #include <asm/mmu.h>
18 #include <asm/pgtable.h>
19 #include <asm/pgalloc.h>
20 #include <asm/pte-walk.h>
21 
22 /*
23  * Supported radix tree geometry.
24  * Like p9, we support either 5 or 9 bits at the first (lowest) level,
25  * for a page size of 64k or 4k.
26  */
27 static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 };
28 
29 int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
30 			   struct kvmppc_pte *gpte, bool data, bool iswrite)
31 {
32 	struct kvm *kvm = vcpu->kvm;
33 	u32 pid;
34 	int ret, level, ps;
35 	__be64 prte, rpte;
36 	unsigned long ptbl;
37 	unsigned long root, pte, index;
38 	unsigned long rts, bits, offset;
39 	unsigned long gpa;
40 	unsigned long proc_tbl_size;
41 
42 	/* Work out effective PID */
43 	switch (eaddr >> 62) {
44 	case 0:
45 		pid = vcpu->arch.pid;
46 		break;
47 	case 3:
48 		pid = 0;
49 		break;
50 	default:
51 		return -EINVAL;
52 	}
53 	proc_tbl_size = 1 << ((kvm->arch.process_table & PRTS_MASK) + 12);
54 	if (pid * 16 >= proc_tbl_size)
55 		return -EINVAL;
56 
57 	/* Read partition table to find root of tree for effective PID */
58 	ptbl = (kvm->arch.process_table & PRTB_MASK) + (pid * 16);
59 	ret = kvm_read_guest(kvm, ptbl, &prte, sizeof(prte));
60 	if (ret)
61 		return ret;
62 
63 	root = be64_to_cpu(prte);
64 	rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) |
65 		((root & RTS2_MASK) >> RTS2_SHIFT);
66 	bits = root & RPDS_MASK;
67 	root = root & RPDB_MASK;
68 
69 	/* P9 DD1 interprets RTS (radix tree size) differently */
70 	offset = rts + 31;
71 	if (cpu_has_feature(CPU_FTR_POWER9_DD1))
72 		offset -= 3;
73 
74 	/* current implementations only support 52-bit space */
75 	if (offset != 52)
76 		return -EINVAL;
77 
78 	for (level = 3; level >= 0; --level) {
79 		if (level && bits != p9_supported_radix_bits[level])
80 			return -EINVAL;
81 		if (level == 0 && !(bits == 5 || bits == 9))
82 			return -EINVAL;
83 		offset -= bits;
84 		index = (eaddr >> offset) & ((1UL << bits) - 1);
85 		/* check that low bits of page table base are zero */
86 		if (root & ((1UL << (bits + 3)) - 1))
87 			return -EINVAL;
88 		ret = kvm_read_guest(kvm, root + index * 8,
89 				     &rpte, sizeof(rpte));
90 		if (ret)
91 			return ret;
92 		pte = __be64_to_cpu(rpte);
93 		if (!(pte & _PAGE_PRESENT))
94 			return -ENOENT;
95 		if (pte & _PAGE_PTE)
96 			break;
97 		bits = pte & 0x1f;
98 		root = pte & 0x0fffffffffffff00ul;
99 	}
100 	/* need a leaf at lowest level; 512GB pages not supported */
101 	if (level < 0 || level == 3)
102 		return -EINVAL;
103 
104 	/* offset is now log base 2 of the page size */
105 	gpa = pte & 0x01fffffffffff000ul;
106 	if (gpa & ((1ul << offset) - 1))
107 		return -EINVAL;
108 	gpa += eaddr & ((1ul << offset) - 1);
109 	for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps)
110 		if (offset == mmu_psize_defs[ps].shift)
111 			break;
112 	gpte->page_size = ps;
113 
114 	gpte->eaddr = eaddr;
115 	gpte->raddr = gpa;
116 
117 	/* Work out permissions */
118 	gpte->may_read = !!(pte & _PAGE_READ);
119 	gpte->may_write = !!(pte & _PAGE_WRITE);
120 	gpte->may_execute = !!(pte & _PAGE_EXEC);
121 	if (kvmppc_get_msr(vcpu) & MSR_PR) {
122 		if (pte & _PAGE_PRIVILEGED) {
123 			gpte->may_read = 0;
124 			gpte->may_write = 0;
125 			gpte->may_execute = 0;
126 		}
127 	} else {
128 		if (!(pte & _PAGE_PRIVILEGED)) {
129 			/* Check AMR/IAMR to see if strict mode is in force */
130 			if (vcpu->arch.amr & (1ul << 62))
131 				gpte->may_read = 0;
132 			if (vcpu->arch.amr & (1ul << 63))
133 				gpte->may_write = 0;
134 			if (vcpu->arch.iamr & (1ul << 62))
135 				gpte->may_execute = 0;
136 		}
137 	}
138 
139 	return 0;
140 }
141 
142 #ifdef CONFIG_PPC_64K_PAGES
143 #define MMU_BASE_PSIZE	MMU_PAGE_64K
144 #else
145 #define MMU_BASE_PSIZE	MMU_PAGE_4K
146 #endif
147 
148 static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr,
149 				    unsigned int pshift)
150 {
151 	int psize = MMU_BASE_PSIZE;
152 
153 	if (pshift >= PMD_SHIFT)
154 		psize = MMU_PAGE_2M;
155 	addr &= ~0xfffUL;
156 	addr |= mmu_psize_defs[psize].ap << 5;
157 	asm volatile("ptesync": : :"memory");
158 	asm volatile(PPC_TLBIE_5(%0, %1, 0, 0, 1)
159 		     : : "r" (addr), "r" (kvm->arch.lpid) : "memory");
160 	asm volatile("ptesync": : :"memory");
161 }
162 
163 unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep,
164 				      unsigned long clr, unsigned long set,
165 				      unsigned long addr, unsigned int shift)
166 {
167 	unsigned long old = 0;
168 
169 	if (!(clr & _PAGE_PRESENT) && cpu_has_feature(CPU_FTR_POWER9_DD1) &&
170 	    pte_present(*ptep)) {
171 		/* have to invalidate it first */
172 		old = __radix_pte_update(ptep, _PAGE_PRESENT, 0);
173 		kvmppc_radix_tlbie_page(kvm, addr, shift);
174 		set |= _PAGE_PRESENT;
175 		old &= _PAGE_PRESENT;
176 	}
177 	return __radix_pte_update(ptep, clr, set) | old;
178 }
179 
180 void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr,
181 			     pte_t *ptep, pte_t pte)
182 {
183 	radix__set_pte_at(kvm->mm, addr, ptep, pte, 0);
184 }
185 
186 static struct kmem_cache *kvm_pte_cache;
187 
188 static pte_t *kvmppc_pte_alloc(void)
189 {
190 	return kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL);
191 }
192 
193 static void kvmppc_pte_free(pte_t *ptep)
194 {
195 	kmem_cache_free(kvm_pte_cache, ptep);
196 }
197 
198 /* Like pmd_huge() and pmd_large(), but works regardless of config options */
199 static inline int pmd_is_leaf(pmd_t pmd)
200 {
201 	return !!(pmd_val(pmd) & _PAGE_PTE);
202 }
203 
204 static int kvmppc_create_pte(struct kvm *kvm, pte_t pte, unsigned long gpa,
205 			     unsigned int level, unsigned long mmu_seq)
206 {
207 	pgd_t *pgd;
208 	pud_t *pud, *new_pud = NULL;
209 	pmd_t *pmd, *new_pmd = NULL;
210 	pte_t *ptep, *new_ptep = NULL;
211 	unsigned long old;
212 	int ret;
213 
214 	/* Traverse the guest's 2nd-level tree, allocate new levels needed */
215 	pgd = kvm->arch.pgtable + pgd_index(gpa);
216 	pud = NULL;
217 	if (pgd_present(*pgd))
218 		pud = pud_offset(pgd, gpa);
219 	else
220 		new_pud = pud_alloc_one(kvm->mm, gpa);
221 
222 	pmd = NULL;
223 	if (pud && pud_present(*pud))
224 		pmd = pmd_offset(pud, gpa);
225 	else
226 		new_pmd = pmd_alloc_one(kvm->mm, gpa);
227 
228 	if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd)))
229 		new_ptep = kvmppc_pte_alloc();
230 
231 	/* Check if we might have been invalidated; let the guest retry if so */
232 	spin_lock(&kvm->mmu_lock);
233 	ret = -EAGAIN;
234 	if (mmu_notifier_retry(kvm, mmu_seq))
235 		goto out_unlock;
236 
237 	/* Now traverse again under the lock and change the tree */
238 	ret = -ENOMEM;
239 	if (pgd_none(*pgd)) {
240 		if (!new_pud)
241 			goto out_unlock;
242 		pgd_populate(kvm->mm, pgd, new_pud);
243 		new_pud = NULL;
244 	}
245 	pud = pud_offset(pgd, gpa);
246 	if (pud_none(*pud)) {
247 		if (!new_pmd)
248 			goto out_unlock;
249 		pud_populate(kvm->mm, pud, new_pmd);
250 		new_pmd = NULL;
251 	}
252 	pmd = pmd_offset(pud, gpa);
253 	if (pmd_is_leaf(*pmd)) {
254 		unsigned long lgpa = gpa & PMD_MASK;
255 
256 		/*
257 		 * If we raced with another CPU which has just put
258 		 * a 2MB pte in after we saw a pte page, try again.
259 		 */
260 		if (level == 0 && !new_ptep) {
261 			ret = -EAGAIN;
262 			goto out_unlock;
263 		}
264 		/* Valid 2MB page here already, remove it */
265 		old = kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd),
266 					      ~0UL, 0, lgpa, PMD_SHIFT);
267 		kvmppc_radix_tlbie_page(kvm, lgpa, PMD_SHIFT);
268 		if (old & _PAGE_DIRTY) {
269 			unsigned long gfn = lgpa >> PAGE_SHIFT;
270 			struct kvm_memory_slot *memslot;
271 			memslot = gfn_to_memslot(kvm, gfn);
272 			if (memslot && memslot->dirty_bitmap)
273 				kvmppc_update_dirty_map(memslot,
274 							gfn, PMD_SIZE);
275 		}
276 	} else if (level == 1 && !pmd_none(*pmd)) {
277 		/*
278 		 * There's a page table page here, but we wanted
279 		 * to install a large page.  Tell the caller and let
280 		 * it try installing a normal page if it wants.
281 		 */
282 		ret = -EBUSY;
283 		goto out_unlock;
284 	}
285 	if (level == 0) {
286 		if (pmd_none(*pmd)) {
287 			if (!new_ptep)
288 				goto out_unlock;
289 			pmd_populate(kvm->mm, pmd, new_ptep);
290 			new_ptep = NULL;
291 		}
292 		ptep = pte_offset_kernel(pmd, gpa);
293 		if (pte_present(*ptep)) {
294 			/* PTE was previously valid, so invalidate it */
295 			old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_PRESENT,
296 						      0, gpa, 0);
297 			kvmppc_radix_tlbie_page(kvm, gpa, 0);
298 			if (old & _PAGE_DIRTY)
299 				mark_page_dirty(kvm, gpa >> PAGE_SHIFT);
300 		}
301 		kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte);
302 	} else {
303 		kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte);
304 	}
305 	ret = 0;
306 
307  out_unlock:
308 	spin_unlock(&kvm->mmu_lock);
309 	if (new_pud)
310 		pud_free(kvm->mm, new_pud);
311 	if (new_pmd)
312 		pmd_free(kvm->mm, new_pmd);
313 	if (new_ptep)
314 		kvmppc_pte_free(new_ptep);
315 	return ret;
316 }
317 
318 int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
319 				   unsigned long ea, unsigned long dsisr)
320 {
321 	struct kvm *kvm = vcpu->kvm;
322 	unsigned long mmu_seq, pte_size;
323 	unsigned long gpa, gfn, hva, pfn;
324 	struct kvm_memory_slot *memslot;
325 	struct page *page = NULL, *pages[1];
326 	long ret, npages, ok;
327 	unsigned int writing;
328 	struct vm_area_struct *vma;
329 	unsigned long flags;
330 	pte_t pte, *ptep;
331 	unsigned long pgflags;
332 	unsigned int shift, level;
333 
334 	/* Check for unusual errors */
335 	if (dsisr & DSISR_UNSUPP_MMU) {
336 		pr_err("KVM: Got unsupported MMU fault\n");
337 		return -EFAULT;
338 	}
339 	if (dsisr & DSISR_BADACCESS) {
340 		/* Reflect to the guest as DSI */
341 		pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr);
342 		kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
343 		return RESUME_GUEST;
344 	}
345 
346 	/* Translate the logical address and get the page */
347 	gpa = vcpu->arch.fault_gpa & ~0xfffUL;
348 	gpa &= ~0xF000000000000000ul;
349 	gfn = gpa >> PAGE_SHIFT;
350 	if (!(dsisr & DSISR_PRTABLE_FAULT))
351 		gpa |= ea & 0xfff;
352 	memslot = gfn_to_memslot(kvm, gfn);
353 
354 	/* No memslot means it's an emulated MMIO region */
355 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
356 		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS |
357 			     DSISR_SET_RC)) {
358 			/*
359 			 * Bad address in guest page table tree, or other
360 			 * unusual error - reflect it to the guest as DSI.
361 			 */
362 			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
363 			return RESUME_GUEST;
364 		}
365 		return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
366 					      dsisr & DSISR_ISSTORE);
367 	}
368 
369 	/* used to check for invalidations in progress */
370 	mmu_seq = kvm->mmu_notifier_seq;
371 	smp_rmb();
372 
373 	writing = (dsisr & DSISR_ISSTORE) != 0;
374 	hva = gfn_to_hva_memslot(memslot, gfn);
375 	if (dsisr & DSISR_SET_RC) {
376 		/*
377 		 * Need to set an R or C bit in the 2nd-level tables;
378 		 * if the relevant bits aren't already set in the linux
379 		 * page tables, fall through to do the gup_fast to
380 		 * set them in the linux page tables too.
381 		 */
382 		ok = 0;
383 		pgflags = _PAGE_ACCESSED;
384 		if (writing)
385 			pgflags |= _PAGE_DIRTY;
386 		local_irq_save(flags);
387 		ptep = find_current_mm_pte(current->mm->pgd, hva, NULL, NULL);
388 		if (ptep) {
389 			pte = READ_ONCE(*ptep);
390 			if (pte_present(pte) &&
391 			    (pte_val(pte) & pgflags) == pgflags)
392 				ok = 1;
393 		}
394 		local_irq_restore(flags);
395 		if (ok) {
396 			spin_lock(&kvm->mmu_lock);
397 			if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
398 				spin_unlock(&kvm->mmu_lock);
399 				return RESUME_GUEST;
400 			}
401 			/*
402 			 * We are walking the secondary page table here. We can do this
403 			 * without disabling irq.
404 			 */
405 			ptep = __find_linux_pte(kvm->arch.pgtable,
406 						gpa, NULL, &shift);
407 			if (ptep && pte_present(*ptep)) {
408 				kvmppc_radix_update_pte(kvm, ptep, 0, pgflags,
409 							gpa, shift);
410 				spin_unlock(&kvm->mmu_lock);
411 				return RESUME_GUEST;
412 			}
413 			spin_unlock(&kvm->mmu_lock);
414 		}
415 	}
416 
417 	ret = -EFAULT;
418 	pfn = 0;
419 	pte_size = PAGE_SIZE;
420 	pgflags = _PAGE_READ | _PAGE_EXEC;
421 	level = 0;
422 	npages = get_user_pages_fast(hva, 1, writing, pages);
423 	if (npages < 1) {
424 		/* Check if it's an I/O mapping */
425 		down_read(&current->mm->mmap_sem);
426 		vma = find_vma(current->mm, hva);
427 		if (vma && vma->vm_start <= hva && hva < vma->vm_end &&
428 		    (vma->vm_flags & VM_PFNMAP)) {
429 			pfn = vma->vm_pgoff +
430 				((hva - vma->vm_start) >> PAGE_SHIFT);
431 			pgflags = pgprot_val(vma->vm_page_prot);
432 		}
433 		up_read(&current->mm->mmap_sem);
434 		if (!pfn)
435 			return -EFAULT;
436 	} else {
437 		page = pages[0];
438 		pfn = page_to_pfn(page);
439 		if (PageCompound(page)) {
440 			pte_size <<= compound_order(compound_head(page));
441 			/* See if we can insert a 2MB large-page PTE here */
442 			if (pte_size >= PMD_SIZE &&
443 			    (gpa & (PMD_SIZE - PAGE_SIZE)) ==
444 			    (hva & (PMD_SIZE - PAGE_SIZE))) {
445 				level = 1;
446 				pfn &= ~((PMD_SIZE >> PAGE_SHIFT) - 1);
447 			}
448 		}
449 		/* See if we can provide write access */
450 		if (writing) {
451 			pgflags |= _PAGE_WRITE;
452 		} else {
453 			local_irq_save(flags);
454 			ptep = find_current_mm_pte(current->mm->pgd,
455 						   hva, NULL, NULL);
456 			if (ptep && pte_write(*ptep))
457 				pgflags |= _PAGE_WRITE;
458 			local_irq_restore(flags);
459 		}
460 	}
461 
462 	/*
463 	 * Compute the PTE value that we need to insert.
464 	 */
465 	pgflags |= _PAGE_PRESENT | _PAGE_PTE | _PAGE_ACCESSED;
466 	if (pgflags & _PAGE_WRITE)
467 		pgflags |= _PAGE_DIRTY;
468 	pte = pfn_pte(pfn, __pgprot(pgflags));
469 
470 	/* Allocate space in the tree and write the PTE */
471 	ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq);
472 	if (ret == -EBUSY) {
473 		/*
474 		 * There's already a PMD where wanted to install a large page;
475 		 * for now, fall back to installing a small page.
476 		 */
477 		level = 0;
478 		pfn |= gfn & ((PMD_SIZE >> PAGE_SHIFT) - 1);
479 		pte = pfn_pte(pfn, __pgprot(pgflags));
480 		ret = kvmppc_create_pte(kvm, pte, gpa, level, mmu_seq);
481 	}
482 
483 	if (page) {
484 		if (!ret && (pgflags & _PAGE_WRITE))
485 			set_page_dirty_lock(page);
486 		put_page(page);
487 	}
488 
489 	if (ret == 0 || ret == -EAGAIN)
490 		ret = RESUME_GUEST;
491 	return ret;
492 }
493 
494 /* Called with kvm->lock held */
495 int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
496 		    unsigned long gfn)
497 {
498 	pte_t *ptep;
499 	unsigned long gpa = gfn << PAGE_SHIFT;
500 	unsigned int shift;
501 	unsigned long old;
502 
503 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
504 	if (ptep && pte_present(*ptep)) {
505 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_PRESENT, 0,
506 					      gpa, shift);
507 		kvmppc_radix_tlbie_page(kvm, gpa, shift);
508 		if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) {
509 			unsigned long npages = 1;
510 			if (shift)
511 				npages = 1ul << (shift - PAGE_SHIFT);
512 			kvmppc_update_dirty_map(memslot, gfn, npages);
513 		}
514 	}
515 	return 0;
516 }
517 
518 /* Called with kvm->lock held */
519 int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
520 		  unsigned long gfn)
521 {
522 	pte_t *ptep;
523 	unsigned long gpa = gfn << PAGE_SHIFT;
524 	unsigned int shift;
525 	int ref = 0;
526 
527 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
528 	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
529 		kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
530 					gpa, shift);
531 		/* XXX need to flush tlb here? */
532 		ref = 1;
533 	}
534 	return ref;
535 }
536 
537 /* Called with kvm->lock held */
538 int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
539 		       unsigned long gfn)
540 {
541 	pte_t *ptep;
542 	unsigned long gpa = gfn << PAGE_SHIFT;
543 	unsigned int shift;
544 	int ref = 0;
545 
546 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
547 	if (ptep && pte_present(*ptep) && pte_young(*ptep))
548 		ref = 1;
549 	return ref;
550 }
551 
552 /* Returns the number of PAGE_SIZE pages that are dirty */
553 static int kvm_radix_test_clear_dirty(struct kvm *kvm,
554 				struct kvm_memory_slot *memslot, int pagenum)
555 {
556 	unsigned long gfn = memslot->base_gfn + pagenum;
557 	unsigned long gpa = gfn << PAGE_SHIFT;
558 	pte_t *ptep;
559 	unsigned int shift;
560 	int ret = 0;
561 
562 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
563 	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
564 		ret = 1;
565 		if (shift)
566 			ret = 1 << (shift - PAGE_SHIFT);
567 		kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,
568 					gpa, shift);
569 		kvmppc_radix_tlbie_page(kvm, gpa, shift);
570 	}
571 	return ret;
572 }
573 
574 long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm,
575 			struct kvm_memory_slot *memslot, unsigned long *map)
576 {
577 	unsigned long i, j;
578 	int npages;
579 
580 	for (i = 0; i < memslot->npages; i = j) {
581 		npages = kvm_radix_test_clear_dirty(kvm, memslot, i);
582 
583 		/*
584 		 * Note that if npages > 0 then i must be a multiple of npages,
585 		 * since huge pages are only used to back the guest at guest
586 		 * real addresses that are a multiple of their size.
587 		 * Since we have at most one PTE covering any given guest
588 		 * real address, if npages > 1 we can skip to i + npages.
589 		 */
590 		j = i + 1;
591 		if (npages) {
592 			set_dirty_bits(map, i, npages);
593 			j = i + npages;
594 		}
595 	}
596 	return 0;
597 }
598 
599 static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info,
600 				 int psize, int *indexp)
601 {
602 	if (!mmu_psize_defs[psize].shift)
603 		return;
604 	info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift |
605 		(mmu_psize_defs[psize].ap << 29);
606 	++(*indexp);
607 }
608 
609 int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info)
610 {
611 	int i;
612 
613 	if (!radix_enabled())
614 		return -EINVAL;
615 	memset(info, 0, sizeof(*info));
616 
617 	/* 4k page size */
618 	info->geometries[0].page_shift = 12;
619 	info->geometries[0].level_bits[0] = 9;
620 	for (i = 1; i < 4; ++i)
621 		info->geometries[0].level_bits[i] = p9_supported_radix_bits[i];
622 	/* 64k page size */
623 	info->geometries[1].page_shift = 16;
624 	for (i = 0; i < 4; ++i)
625 		info->geometries[1].level_bits[i] = p9_supported_radix_bits[i];
626 
627 	i = 0;
628 	add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i);
629 	add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i);
630 	add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i);
631 	add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i);
632 
633 	return 0;
634 }
635 
636 int kvmppc_init_vm_radix(struct kvm *kvm)
637 {
638 	kvm->arch.pgtable = pgd_alloc(kvm->mm);
639 	if (!kvm->arch.pgtable)
640 		return -ENOMEM;
641 	return 0;
642 }
643 
644 void kvmppc_free_radix(struct kvm *kvm)
645 {
646 	unsigned long ig, iu, im;
647 	pte_t *pte;
648 	pmd_t *pmd;
649 	pud_t *pud;
650 	pgd_t *pgd;
651 
652 	if (!kvm->arch.pgtable)
653 		return;
654 	pgd = kvm->arch.pgtable;
655 	for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
656 		if (!pgd_present(*pgd))
657 			continue;
658 		pud = pud_offset(pgd, 0);
659 		for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++pud) {
660 			if (!pud_present(*pud))
661 				continue;
662 			pmd = pmd_offset(pud, 0);
663 			for (im = 0; im < PTRS_PER_PMD; ++im, ++pmd) {
664 				if (pmd_is_leaf(*pmd)) {
665 					pmd_clear(pmd);
666 					continue;
667 				}
668 				if (!pmd_present(*pmd))
669 					continue;
670 				pte = pte_offset_map(pmd, 0);
671 				memset(pte, 0, sizeof(long) << PTE_INDEX_SIZE);
672 				kvmppc_pte_free(pte);
673 				pmd_clear(pmd);
674 			}
675 			pmd_free(kvm->mm, pmd_offset(pud, 0));
676 			pud_clear(pud);
677 		}
678 		pud_free(kvm->mm, pud_offset(pgd, 0));
679 		pgd_clear(pgd);
680 	}
681 	pgd_free(kvm->mm, kvm->arch.pgtable);
682 	kvm->arch.pgtable = NULL;
683 }
684 
685 static void pte_ctor(void *addr)
686 {
687 	memset(addr, 0, PTE_TABLE_SIZE);
688 }
689 
690 int kvmppc_radix_init(void)
691 {
692 	unsigned long size = sizeof(void *) << PTE_INDEX_SIZE;
693 
694 	kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, 0, pte_ctor);
695 	if (!kvm_pte_cache)
696 		return -ENOMEM;
697 	return 0;
698 }
699 
700 void kvmppc_radix_exit(void)
701 {
702 	kmem_cache_destroy(kvm_pte_cache);
703 }
704